There are few natural disasters that pose a threat to our species. However, super volcanoes have devastated the global biosphere in the past and if one were to occur today, it would seriously destabilize our civilization. At the moment our knowledge of super volcanoes is impoverished but current evidence suggests that there is one underneath Yellowstone National Park that could erupt soon on a geologic time scale.
At least that one isn't our fault. At least not directly. I suppose the fanatics that blamed Hurricane Katrina on sinners can blame a super volcano in Yellowstone on us as well.Although the Yellowstone supervolcano seems to be on a much longer cycle of approximately 2.0 million years, the last eruption occurred 2.1 million years ago producing one of the largest known eruptions in natural history.
I remember reading that if the Yellowstone Caldera exploded, we'd have about knee-deep ash here in Detroit. A couple of years ago there was a string of quakes under the lake there, several per day. They happen all the time. Of course, that mostly has to do with odds, and the span of a human lifetime. It's not because the caldera is going to give us a lifetime's worth of warning. :)Luckily, most volcanologists agree that we shouldn’t expect the Yellowstone super volcano to erupt in our lifetime.
Most definitely. It could blow in a month - or it could blow in 100,000 years. Volcanologists just don't know. The only thing that is certain - is that it will blow soon on a geologic time scale.